Change hardcoded ~/.oh-my-zsh to $ZSH.

lib/completion.zsh

@@ -46,7 +46,7 @@ zstyle ':completion:*:hosts' hosts $hosts
 
 # Use caching so that commands like apt and dpkg complete are useable
 zstyle ':completion::complete:*' use-cache 1
-zstyle ':completion::complete:*' cache-path ~/.oh-my-zsh/cache/
+zstyle ':completion::complete:*' cache-path $ZSH/cache/
 
 # Don't complete uninteresting users
 zstyle ':completion:*:*:*:users' ignored-patterns \